The present invention relates to the sewing of a slide fastener into a slit formed in a carrier material that is composed of an upper and at least one lower layer.
More particularly, the invention relates to a method of so sewing the slide fastener to the carrier material, and to an arrangement for carrying out the method.
In some instances, a slide fastener is to be sewn only to a single layer carrier material. There are, however, many instances in which a slide fastener must be sewn to a carrier material which is formed with a slit into which the slide fastener is to be secured, and which carrier material is composed of an upper and at least one lower layer. For example, the perhaps most frequent application of this type is when a slide fastener must be sewn to a garment, such as a skirt or the like, that is composed of the outer layer of material and an inner layer of lining material.
For this purpose, the prior art provides arrangements which use twin-needle or multiple-needle sewing machines and in which the entire operation of supplying the material and the slide fastener, orienting them relative to one another and sewing the slide fastener to the material, is carried fully automatically without requiring any manual guidance by an operator. However, while this part of the operation is automated, the prior arrangement of the material and the slide fastener with reference to one another, before the equipment takes over for the automatic supplying to the sewing machine, and the sewing of the slide fastener to the carrier material, must be carried out manually. The guiding devices for the material and the slide fastener which are required in this prior-art arrangement are so complicated that the insertion of the material in the slide fastener into these guiding devices requires an inordinate amount of manual labor which has no reasonable relationship to the amount of time that is saved by automating the subsequent operations. Thus, all or substantially the time that is saved by the subsequent automatic operations is lost by the preliminary manual handling that is required.
Other prior-art proposals suffer from analogous disadvantages, including the fact that some of them make it almost impossible for the operator to have access to the needle area of the sewing machine and that in some instances only an endless slide fastener can be employed, rather than a slide fastener of predetermined length, in which case a part of the slide fastener that is being withdrawn from an endless supply is sewn in place and is then cut off from the supply.